1. Field of the Invention
The present invention relates in general to a liquid crystal display with an electrostatic discharge guide, and more particularly to a liquid crystal display with a structure guiding electrostatic discharge to occur at a specific location.
2. Description of the Related Art
Electrostatic discharge, abbreviated as ESD in the following description, may occur during measurement, assembly, installation, and use in integrated circuits and liquid crystal displays and may damage the circuits or devices therein. Furthermore, function of the entire system may be affected. The three models often explain the causes of ESD stress. The first ESD stress model of the Human Body Model (HBM) refers to ESD stress caused by discharge when a charged human body touches a device under test (DUT). The second ESD stress model of the Machine Model (MM) refers to ESD stress caused by discharge when a charged machine contacts a device under test (DUT). The third ESD stress model of the Charged Device Model (CDM) refers to ESD stress caused by discharge when a charged DUT contacts a conductor which is at a different voltage potential.
In the fabrication process of a thin film transistor liquid crystal display (TFT-LCD), a panel is processed by many machines and operators. Inevitably, electrostatic charge builds up. Electrostatic charge that is not released in some way is harmful to the TFT-LCD. Typically, the Joule heat generated during discharge causes ESD damage to a TFT-LCD. Joule heat may result in a short circuit between two isolated conductors or an open circuit caused by melted conductive wire. Both types of damage may cause the TFT LCD to malfunction.
Damage can be detected by electrical testing subsequent to fabrication of a liquid crystal display. However, TFT-LCD is large devices measured in inches while the physical dimensions of ESD damage is measured in micrometers. Thus rapid determination of location of ESD damage in a large size display and rapid repair thereof are important issues. Overcoming either or both issues can enhance the repair rate and improve yield.